Stacks of interlinked material sheets, such as tissue sheets, or material sheets made of non-woven or equivalent flexible wiping materials, are usually folded so that they occupy as limited an area as possible at the same time as they provide sheets with maximum unfolded area. For the user, it is often desirable that material sheets for, for example, wiping purposes occupy as small an area as possible in stack form, as stacks of material sheets are often placed on tables or other surfaces with limited space.
Within the technical field, sheets which have been folded individually once or a number of times and thus provided with a corresponding V, Z or W appearance are well known. The material sheets have subsequently been folded into one another with one or more parts in order to form a continuous stack of sheets. An advantage of this type of interfolding is that, when the stack of sheets is packed in a dispenser, the removal of a sheet from the stack of sheets brings about automatic feeding-out of the next sheet through a dispensing opening present in the dispenser. The sheet extracted then also acquires its full area which is then available for immediate use.
When the sheets are folded in only one direction, however, the problem remains that the stack of sheets retains its full extent in the non-folded direction. The reduction in area which it is desired to achieve in connection with the folded material sheets is then achieved in only one direction, which results in a stack of material sheets which takes up a relatively large area. Limiting the sheets in the non-folded direction in order to reduce the surface area of the stack results in sheets which have a small width in relation to the length after extraction as well. The user often feels that this type of material sheet is entirely inadequate as wiping, especially of large areas, can be performed best if the sheets are both long and wide.
Another problem with this type of folding of material sheets arises furthermore when a certain number of material sheets have already been removed from the dispenser in which they are packed. A prerequisite for the holding-together capacity between two conventionally folded material sheets is that the interlinking angle which is brought about in the folding of a material sheet is sufficiently acute. The purpose of the acute angle is then to grip around the next material sheet and thus establish secure interlinking between the material sheets. When a top material sheet is removed through a dispensing opening, the distance to the next material sheet increases relatively promptly. As a consequence of the interlinking angle increasing, the risk of the material sheets sliding out of the interlinking grip increases. In such a situation, the next material sheet may then drop down from the opening of the pack towards the interior of the pack, where it is difficult for the user to reach it.
In a conventionally arranged stack of material sheets, moreover, it is difficult for the material sheets arranged last to reach up to a conventionally designed dispensing opening in a dispenser as the material sheets often have an extent which means that the length with which the last material sheets can extend out through a dispensing opening is limited.
Attempts to counteract the abovementioned problems with stacks of interlinked material sheets packed in a dispenser have resulted in shallower packs, which has in turn led to problems of insufficient material sheet storage capacity. In addition, a risk remains that, in spite of the pack height being limited, the next sheet may still slide out of the interlinking folding grip.
There is consequently a great need to improve the folding with which a stack of material sheets is interlinked, so that the dispensing of material sheets from a stack of sheets is guaranteed at the same time as the user is provided with a material sheet of very good size. In addition, there is a need for a method in which the material sheets are interfolded in a simple and appropriate manner to form a stack of sheets of the kind mentioned above.